plug chop pic need help

[fxnteeth]

OK guys, this is a pic from a plug chop. This is a 265cc with an 38mm PWK Keihin airstriker, unifilter. 175 main jet and stock sizes on the other jets. Bike runs great until very high rpms. It stutters with a 150 main all the way to the 175 main. 93 octane 32:1 Klotz. Not sure how to get the stutter out. The chop seems to be ok to me with a tan band at wot. Dont know the elevation, i am in central Louisiana. 65 degrees. What else may be causing the stutter at wot. thank you
Jarrod

[cr480r]

ignition... had a suzuki that did that same thing.. tried different fuels, petcock, cdi's, timing, and main jets from 150-200 with no cure... the bike was a rocket after I replaced the stator.. the faulty stator tested good and it always started and ran great until the main jet.. the problem became noticably worse as i added performance parts, pipe, compression, carb, etc... my guess was the increased cylinder pressure was blowing out the spark past 3/4 throttle

[fxnteeth]

So a new ignition coil may be all I need?

[Slingblade]

Start by cleaning all connections from the stator all the way to the plug wire. Use a little dielectric grease on them. Clean up your grounds and make sure they're tight. Then take your plug out, put in the cap, ground it to the head, kick it over and check to see if you've got a bright spark. Sometimes corrosion can rob some spark that might not show up till higher rpm's or under a load. It may not fix it but always do the stuff that's free before you start spending on parts. Good Luck.

[4cfed]

can also try gapping down the plug

[fxnteeth]

What is a good ignition system? Brand?

[beets442]

Chop looks good too. Did you check the gas cap vent and hose, if it gets parked for while humidity will rust that small hole closed?...Beets

[fxnteeth]

Yes, the gas cap and vent are all plastic. It is clear. I am getting a decent spark when I take the plug out and put the cap on and kick it. How do I test the stator and on down the line? It is a new dynatek ignition box and a new coil. Possibly the stator? I have also tried many new spark plugs. thank you
Jarrod

[beets442]

I'd check timing, compression too. How did it run before it was worked on?

[Billy Golightly]

Gap the plug down to between .012 and .018